The present invention concerns a wedge box of an alveolar material formed from at lest two elements such as a container and a lid.
The invention also concerns a mould and a process for production of such a box.
Wedge boxes of alveolar material such as expanded polystyrene (PSE) are opaque. There are also boxes (FIG. 1) formed from a container 1 holding a lid 2 of transparent material. This lid 2 is produced by injection moulding or thermomoulding. It is a thin sheet, possibly of the same type as the alveolar material. In the case of a container 1 of expanded polystyrene, the lid 2 may be made of compact polystyrene. The lid 2 has a rim in the form of a peripheral groove to house the rim 11 of container 1. But this lid 2 of very small thickness does not perform the same functions as the alveolar material of container 1. It neither protects the top of the box from impact or crushing nor provides thermal insulation. Also on a logistical level, two processing technologies and hence two suppliers are required, which involves two control and supply lines.
The lid is generally placed as show in FIG. 1. To make a box with a hinger lid such as the box in FIG. 2, the transparent lid 2' must be attached to container 1' via a hinge 3' produced in a separate operation from that of production of container 1' and lid 2'.